This invention relates generally to bearings with encoders and, more particularly, to a device for fixing a data sensor opposite a rolling-element bearing equipped with a coding element that can be read by the sensor.
Publication FR-2,667,947 describes a rotational speed sensing device that is pinched between a shoulder and a fixed ring of a bearing, and mounted by a hoop in its housing. In such a mounting, axial displacement or creep of the bearing may occur as a result of mechanical stresses or of differential expansion. Although the operation of the bearing may be unaffected, because an axial stop using "circlips" is often provided, the operation of the sensor may be affected since the relative position of the sensor with respect to the coding element is modified. In addition, the sensor is no longer firmly maintained, and instead has some play, making it sensitive to vibrations. This can result in oxidation of the contacts and micro short circuits, reducing reliability of the signal. And, in the case of a rotating internal ring, centrifugation of pollutants may occur, causing friction, heat, and wear. Finally, such a mounting requires modification of the housing and does not allow independent replacement of sensor and bearing elements.
U.S. Pat. Nos. 5,143,458 and 5,451,869 describe supports for sensors that are elastically fixed to a fixed ring of a bearing, thus eliminating some of the disadvantages described above. However, the engagement between the resilient support member and the fixed ring of the bearing with such configurations requires specific arrangements on the fixed ring. These arrangements can lead to the reconsideration of the mounting conditions of the bearing because of a reduction in the size of the rolling-elements or in the space dedicated to the integrated seal of the bearing. In addition, the resulting diversity of bearings can generate large cost increases, either with regard to the bearing components themselves, or with regard to the inventory requirements at the user's site.
The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.